For:
By: Daniel E. Mullins
Extension Horticulture Agent
Is Aromatherapy for Plants Possible?
Researchers have
been working for years to develop effective alternative soil fumigants that are
safe on the environment. Since methyl
bromide, the Cadillac of soil treatment products for high value commercial
vegetable crops is expected to be banned in the
Many long time home gardeners also battle soil borne pests, especially where intensive planting is done. We would also like to have a safe, effective product that could be applied to treat the soil prior to planting vegetables and flowers.
The
possibility of using the essential oils as soil fumigants is getting a lot of attention from
several
In studying the essential oils it was found that some have been used in traditional medicine as solutions for bacterial infections and other illnesses. Further study revealed that the natural chemicals in these oils are effective against soil-borne diseases caused by bacteria and fungi.
Another characteristic of essential oils is that they are highly volatile, filling a room with their aroma in a matter of seconds. The ability to change to vapor quickly is highly desirable in a fumigant. This property allows them to penetrate soil, kill pests and then quickly evaporate, leaving no residue.
Thyme (Thymol) and palmarosa oil have undergone testing on two crops of commercial tomatoes to date. The main goal of this study was to determine if these essential oil treatments would reduce the incidence of bacterial wilt.
Thyme oil was more effective than palmarosa oil. In a 2003 field trial thymol significantly reduced the bacterial wilt incidence on a susceptible tomato variety. While only twelve per cent of plants wilted and died in the treated plots, over 65 percent died in the untreated plots.
Thymol is safe for human consumption at low doses. It is so safe that the U.S. Food and Drug Administration allows its use as a food additive. At high concentrations, the chemical is known to cause skin and lung irritations in humans. However, the researchers say that it can be applied in a way that prevents the user from receiving a strong dose of the chemical.
While applying thyme and palmarosa oil to crops on a large scale wouldn’t be cost effective, thymol can be produced at low cost. Research at other institutions has identified other essensial oils with pest controlling properties.
Don’t expect to be able to run down to the local garden center and purchase packaged essential oil for treating the garden soil in the near future. However, we might some day be able to grow healthier plants using aromatherapy.
Stay tuned and learn more about this fascinating subject. The complete story, which I have paraphrased here, is available online at http://news.ifas.ufl.edu/story.php?id=816.
Question of the Week: Large mushrooms continue to emerge from one spot in my yard. What can I use to control them?
Answer: The repeated
emergence of mushrooms from the same place indicates that there is a food
source underground. Most of the large
mushrooms are the fruiting structures of saprophytic fungi. These fungi are decomposers, helping to break
down organic material. There is probably
some buried dead wood in that area. It
might be a large dead root, lumber or a stump.
Find it and remove it and the problem should go away.